Liquid Filtering Bag

ABSTRACT

A liquid filtering bag comprises a liquid-permeable fabric and zipper. When the zipper is fully engaged, the fabric folds to form a liquid filtering bag suitable for filtering liquids. When the zipper is fully disengaged, the fabric unfolds to form a flat sheet suitable for thorough washing.

BACKGROUND OF THE INVENTION

The liquid filtering bag is an important device used in the preparationof many beverages such as cold-brewed coffee, nut milk, and juice. Aliquid filtering bag is also an important device used in the preparationof infused oils. Reusable liquid filtering bags are typicallymanufactured from fabrics that allow them to be washed and reused manytimes.

Those skilled in the art find that currently available reusable liquidfiltering bags suffer from limitations related to gradual fouling andclogging and consequent loss of efficacy. During the filtering process,solid particles, fats and waxes become lodged inside the meshwork of thefiltering bag. As the meshwork accumulates debris, the effective size ofthe pores decreases, resistance to flow increases, and the filteringperformance of the filtering bag degrades.

There are various ways to wash a reusable filtering bag to removeembedded debris and restore filter performance. Handwashing canpartially restore filter performance, though handwashing is laborintensive, requires manual turning inside-out, exposes the operator toskin-irritating detergents, and requires multiple cycles of washing andrinsing. After handwashing the filtering bag, subsequent machine washingcan further remove embedded debris, but machine washing typically failsto fully restore the performance of the filtering bag. As a result,those skilled in the art find that currently available reusable liquidfiltering bags require significantly labor-intensive handwashing priorto machine washing and yet tend to steadily lose performance after everyinterval of filtering and washing and that after some number ofintervals they need to be discarded.

In U.S. Pat. No. 9,919,247, Wettlaufer describes a seamless filter bagfor a juice press. The open-top bag is formed by folding a singlecontinuous sheet of fabric in half, then crimping the right and leftsides with folds that are held in place with one or more belts. Whensaid bag is unfolded, the single continuous sheet of fabric would besuitable for machine laundering. However, in operation, said bag issqueezed between two platens with up to seven tons of force whichrequires a large and expensive press that may only be suitable for afactory or store distributing bottled juice.

In U.S. Pat. No. 6,908,550, Silverstein describes a filter bag for apool cleaning device with a zipper opening along one side. The zipperopening allows for temporary access to the interior of the bag to removecollected debris. Based on the described embodiments of the invention,it is anticipated that said bag would not be suitable for machinelaundering.

In U.S. Pat. No. 10,743,557, Hampton et. al. describe a nutmilkextraction device utilizing an open-top filtering bag that is suspendedinside an extraction chamber. The bag is twistably compressed by atwistable cap on the device. Based on the described embodiments of theinvention, it is anticipated that said bag would not be suitable formachine laundering.

Despite the available art described in the patents, there remains alarge unmet need for reusable liquid filtering bags that canconveniently process infused oils and beverages such as cold-brewcoffee, nut milks, and juices and that can be more easily cleaned andmore fully restored to their original filtering performance after everywashing. There is also a large unmet need in commercial kitchens andrestaurants for filtering bags that can be conveniently washed in alaundry machine and reused in a way that meets stringent sanitationregulations. Such a reusable filtering bag would help support andpromote the current consumer demand for healthier, cold-brewed beverageand nut milk options.

SUMMARY OF THE INVENTION

The present invention describes a reusable liquid filtering bag that canbe disassembled to form a single continuous sheet of fabric andlaundered in an automatic laundry washing machine. Said bag employs acontinuous zipper along the bottom and side edge. When said zipper isfully engaged, the bottom and side edge of said bag are sealed to forman open-top filtering bag. When said zipper is fully disengaged, saidedges are released and said bag opens to form a single continuous flatsheet of fabric.

It has been discovered that common zippers can be readily incorporatedinto embodiments of the invention without compromising filteringperformance. For context, someone of ordinary skill in the art wouldlikely anticipate the gap between opposing teeth of common zippers wouldpermit filtered particulates to escape the filtering bag and degradefiltering performance. However, common zippers have been discovered tohave such closely engaged opposing teeth that they not only block theescape of particulates, they also sustain this performance underelevated pressures induced by filtering presses.

It has also been discovered that laundering the bag in its unzipped,disassembled form facilitates sufficient removal of embedded debris thatfiltering performance is fully restored after laundering. For context,someone of ordinary skill in the art would likely anticipate thatlaundering the unzipped, disassembled filter would provide anincremental benefit in restoring filtering performance after laundering.Quite unexpectedly, embodiments of the invention appear to retain nearlycomplete filtering performance after many cycles of filtering andwashing while conventional filtering bags made from the identical fabriclose significant filtering performance after a single cycle of filteringand washing.

In some embodiments of the present invention, filtering bags may be talland narrow or may be short and wide. Embodiments may have a bottomzipper-fringed edge that is straight or rounded.

A deeper understanding of the nature and advantages of the presentinvention may be achieved by referring to the drawings and the remainderof the specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a tall and narrow liquid filtering bag in an assembledopen-top bag configuration with the zipper fully engaged. Saidconfiguration represents the state during which said bag can be used tofilter liquids.

FIG. 2 shows a tall and narrow liquid filtering bag in a disassembledflat-sheet configuration with the zipper fully disengaged. Saidconfiguration represents the state during which said bag can be washed,dried, and stored.

FIG. 3 shows a short and wide liquid filtering bag in an assembledopen-top bag configuration with the zipper fully engaged. Saidconfiguration represents the state during which said bag can be used tofilter liquids.

FIG. 4 shows a short and wide liquid filtering bag in a disassembledflat-sheet configuration with the zipper fully disengaged. Saidconfiguration represents the state during which said bag can be washed,dried, and stored.

SPECIFICATIONS

FIG. 1 shows a tall and narrow liquid filtering bag according to apreferred embodiment of the invention. Said bag is shown in an assembledopen-top bag configuration representing the state during which said bagcan be used to filter liquids. An outer surface 10 of said filtering bagexudes filtered liquid during filtering operation. An inner surface 20of said bag receives unfiltered liquid and traps filtered particulatesduring filtering operation. A fully engaged zipper 30 forms the bottomand side edge of said filtering bag. A zipper slider 40 and puller 50are configured to rest at the top edge of said bag when fully engaged.

In embodiments of the invention, the filter bag is made from mesh,fabric, non-woven fabric, fiber, cloth, cotton, nylon, polyester, orcotton paper. Said embodiments are fashioned with a mesh spacingselected from about 25-500 micrometers and preferably 70-150micrometers. Said embodiments are configured with an open top furtherconfigured with one or more closure devices selected from the groupcomprising crimp, fold, flap, clamp, drawstring, zipper, andhook-and-loop fastener.

In embodiments of the invention, the zipper 30 may be selected fromgauge sizes #3 up to #10.It was discovered that said zipper selectedfrom these gauge sizes was sufficiently tightly engaged to prevent theescape of filtered particulates from between its teeth out of the baginto the filtered liquid.

In embodiments of the invention, tall and narrow filtering bags would beselected from sizes that can conveniently process about 200-10000milliliters of unfiltered liquid and preferably 500-2000 milliliters ofunfiltered liquid. Said embodiments have a height of about 200-900millimeters and preferably 300-500 millimeters. Said embodiments have awidth of about 100-500 millimeters and preferably 150-250 millimeters.Said embodiments have a height to width ratio of about 1.5 to 3 andpreferably around 2.

It was discovered that when reduced to practice, a tall and narrowliquid filtering bag is ideally suited for many food and beveragefiltering tasks when it is supported by a tall and narrow supportingpitcher common to most kitchens because the bag is less sufficientlystable to staying upright on its own during filling.

FIG. 2 shows a tall and narrow liquid filtering bag in a disassembled,flat-sheet configuration according to a preferred embodiment of theinvention. The flat-sheet configuration represents the state duringwhich said bag can be washed, dried, and stored. A visible, formerlyouter surface 10 and hidden, formerly inner surface 20 are fully exposedto laundering agents and washing water during automatic machine washing.The fully exposed surfaces facilitate the unhindered release of trappeddebris from said surface 20 directly into the bulk phase of washingwater. A fully disengaged zipper 30 forms the bottom edge and both sideedges of said disassembled filtering bag. A zipper slider 40 and puller50 are configured to rest at the innermost center of bottom edge of saidbag where the two opposing zipper edges remain connected when fullydisengaged.

In preferred embodiments of the invention, disassembled filtering bagswould be washable in an automatic washing machine without the need forextensive hand pre-washing. Said filtering bags would also be compatiblewith high-temperature washing, disinfection, and high-temperature dryingin order to ensure proper sanitation for reuse in a commercial foodestablishment.

In embodiments of the invention, the disassembled, flat-sheetconfigurations of tall and narrow filtering bags have height of about200-900 millimeters and preferably 300-500 millimeters. Said embodimentshave a width of about 200-900 millimeters and preferably 300-500millimeters. Said embodiments have a height to width ratio of around0.75 to 1.5 and preferably around 1.

It was discovered that laundering the disassembled, flat-sheetconfiguration of filtering bags was far more effective than launderingof a conventional filtering bag; nearly all the original filteringperformance of the filtering bag could be retained after every cycle offiltering, washing, and drying. The superior filtration performance ofembodiments of the invention after washing has enabled their use withmore challenging filtration tasks involving finer particulates, which,in turn, has enabled the development of unprecedented new techniques ofcold brew beverage production involving much finer grinding and betterflavor extraction from brewing materials than previously anticipated.

FIG. 3 shows a short and wide liquid filtering bag according to apreferred embodiment of the invention. Said bag is shown in fullyassembled configuration representing the state during which said bag canbe used to filter liquids. An outer surface 10 of said filtering bagexudes filtered liquid during filtering operation. An inner surface 20of said bag receives unfiltered liquid and collects filteredparticulates during filtering operation. A fully engaged zipper 30 formsbottom and side edge of said filtering bag. A zipper slider 40 andpuller 50 are configured to rest at the top edge of said bag when fullyengaged.

In embodiments of the invention, short and wide filtering bags would beselected from sizes that can conveniently process about 200-10000milliliters of unfiltered liquid and preferably 500-2000 milliliters ofunfiltered liquid. Said embodiments have a height of about 150-700millimeters and preferably 200-400 millimeters. Said embodiments have awidth of about 150-700 millimeters and preferably 200-400 millimeters.Said embodiments have a height to width ratio of about 0.75 to 1.5 andpreferably around 1.

It was discovered that when reduced to practice, a short and wide liquidfiltering bag is ideally suited for many food and beverage filteringtasks when it is supported by a flat pan or shallow pot common to mostkitchens because the bag is more sufficiently stable to staying uprighton its own during filling.

FIG. 4 shows a short and wide liquid filtering bag in a fullydisassembled configuration representing the state during which said bagcan be washed, dried, and stored. A visible, formerly outer surface 10and hidden, formerly inner surface 20 are fully exposed to launderingagents and washing water during automatic machine washing enabling thecomplete release of trapped debris from said surface 20. A fullydisengaged zipper 30 forms the bottom and both side edges of saiddisassembled filtering bag. A zipper slider 40 and puller 50 areconfigured to rest at the innermost center of bottom edge of said bagwhere the two opposing zipper edges remain connected when fullydisengaged.

In embodiments of the invention, short and wide filtering bags in afully disassembled configuration have a height of about 150-700millimeters and preferably 200-400 millimeters. Said embodiments have awidth of about 300-1300 millimeters and preferably 500-700 millimeters.Said embodiments have a height to width ratio of about 0.25 to 0.75 andpreferably around 0.5.

While the above text and accompanying figures are a complete descriptionof specific embodiments of the invention, they should not be taken aslimiting the scope of the invention as defined by the claims. Forinstance, the filtering bags described by this invention could beimplemented for the separation of any solid and liquid mixture that mayor may not be beverage or aqueous. The filtering bags could beimplemented to operate at any given temperature and pressure.

1. A liquid filter comprising: a single unitary sheet; and a zipperhaving a gauge size between #3 and #10, the zipper being disposed on aportion of a perimeter of the single unitary sheet, wherein the singleunitary sheet comprises a liquid-permeable fabric, wherein engaging thezipper forms the single unitary sheet into a pouch configuration with anopening, wherein, when an unfiltered liquid is received in the pouchconfiguration, the liquid-permeable fabric of the liquid filter retainsparticulates of the unfiltered liquid, wherein the opening comprises aclosure device, wherein disengaging the zipper forms the single unitarysheet into a flat configuration, and wherein the flat configuration ofthe single unitary sheet is machine-washable to remove debris from theliquid-permeable fabric. 2.-6. (canceled)
 7. The liquid filter of claim1, wherein the pouch configuration comprises: a height from a lower edgeof a bottom portion to an upper edge of the opening proximate a topportion that is in a range of 200-900 millimeters, wherein the bottomportion is disposed opposite the top portion, a width from a first sideto a second side that is in a range of 100-500 millimeters, wherein thefirst side is disposed opposite the second side, and a height to widthratio in a range of 1.5 to
 3. 8. The liquid filter of claim 7, wherein:the height is in the range of 300-500 millimeters, the width is in therange of 150-250 millimeters, and the height to width ratio is
 2. 9. Theliquid filter of claim 1, wherein the flat configuration comprises: aheight from a lower edge of a bottom portion to an upper edge of a topportion that is in a range of 200-900 millimeters, wherein the bottomportion is disposed opposite the top portion, a width from a first sideto a second side that is in a range of 200-900 millimeters, wherein thefirst side is disposed opposite the second side, and a height to widthratio in a range of 0.75 to 1.5.
 10. The liquid filter of claim 9,wherein: the height is in the range of 300-500 millimeters; the width isin the range of 300-500 millimeters; and the height to width ratio is 1.11. The liquid filter of claim 1, wherein the closure device comprises:a fold, a flap, a clamp, a drawstring, another zipper, or ahook-and-loop fastener.
 12. The liquid filter of claim 1, wherein theliquid-permeable fabric comprises: mesh, woven fabric, non-woven fabric,fiber, cloth, cotton, nylon, polyester, or cotton paper.
 13. The liquidfilter of claim 12, wherein the liquid-permeable fabric comprises themesh, and wherein the mesh comprises spacing in a range of 25-500micrometers.
 14. (canceled)
 15. A method to filter a liquid using theliquid filter bag of claim 17, comprising: disengaging the zipper toconvert the liquid filter bag to the flat configuration; washing theflat configuration of the liquid filter bag; folding the flatconfiguration of the liquid filter bag; engaging the zipper to convertthe flat configuration of the liquid filter bag to a pouchconfiguration; and pouring a liquid into the opening of the pouchconfiguration of the liquid filter bag to filter the liquid.
 16. Themethod of claim 15, further comprising: washing the flat configurationof the liquid filter bag; drying the washed flat configuration of theliquid filter bag; and storing the dried flat configuration of theliquid filter bag.
 17. A liquid filter bag comprising: an opening; and abody portion comprising a first side disposed opposite a second side anda bottom portion disposed opposite a top portion, wherein the bodyportion comprises: a single unitary sheet comprising a liquid-permeablefabric; and a zipper disposed on a portion of a perimeter of the bodyportion, wherein: a height from a lower edge of a bottom portion to anupper edge of the opening proximate the top portion that is in a rangeof 150-700 millimeters, a width from the first side to the second sidethat is in a range of 150-700 millimeters, and a height to width ratioin a range of 0.75 to 1.5; wherein, when an unfiltered liquid isreceived in the body portion, the liquid-permeable fabric of the bodyportion retains particulates of the unfiltered liquid, and whereindisengaging the zipper forms the liquid filter bag into a flatconfiguration that is machine-washable to remove debris from theliquid-permeable fabric.
 18. The liquid filter bag of claim 17, whereinthe washed flat configuration of the liquid filter bag is dryable andstorable.
 19. (canceled)
 20. The liquid filter of claim 17, wherein: theheight is in the range of 200-400 millimeters; the width is in the rangeof 200-400 millimeters, and the height to width ratio is about
 1. 21.(canceled)
 22. The liquid filter of claim 17, wherein: the height is inthe range of 200-400 millimeters; and the width is in the range of500-700 millimeters.